Switch actuating mechanism



April 19, 1932. 0. F. CARLSON SWITCH ACTUATING MECHANISM Original Filed Nov. 22, 1926 2 Sheets-Sheet l r mm w LC m C W07 00 7 April 19, 1932. n F, CARLSON 1,854,540

" 'SWITCH" ACTUATING MECHANISM Original Filed Nov. 22, 1926 2 Sheets-Sheet 2 272/6 7 adv/i 050M1 2 Caglsow,

Patented Apr. 19, 1932 UNITED STATES PATENT. 'orrlcn I OSCAR I. CABLSOH, OI CHICAGO, ILLINOIS, ASSIGNOB, BY MES NE AQSIGNMENTS, 'I'O OLE-HONEYWELL REGULATOR COMPANY, OF MINNEAPOLIS, MINNESOTA,

A CORPORATION OF DELAWARE SWITCH ACTUATING MECHANISI Application fled November 23, 1826, Serial No. 149,888.. Renewed Gctober 1, 1981. I

My invention relates to improvements in switches and particularly to switches for con= trolling the pump motor of an oil burning heating plant in accordance with the steam pressure, vacuum conditions and water level thereof.

The principal object of my invention is to provide a switch mechanism adapted to be actuated by means responsive to boiler conditions for eflecting a quick non-arcing opening and closing of an electric circuit such as the circuit of a motor of an oil burning heating apparatus.

A urther object of the invention is to provide such a switch which may be so adjusted as to open or close the motor circuit at various predetermined steam pressure or vacuum conditions, depending on the principle of the heating apparatus with which the improvements are used.

Further objects of theinvention relate to various features of construction and arrangement of parts which will become apparent from a consideration of the following specification and accompanying drawings, where- Figure 1 is a side elevation showing an embodiment of my improvements associated with apparatus responsive to boiler conditions, parts of said figure being shown broken away and in section for the purpose of able weights.

In the drawings, 10 is a float casing which is attached to a boiler of a heating apparatus (not shown), the said casing being attached to the boiler by means of the taps 11, 11, on which the usual water gauge is mounted. The water gauge is attached to the casing 10 by additional taps (not shown) so it will indicate the height of the water in the boiler as before.

Within the casing 10 is a float 12 attached to the lever 13, pivoted at 14, the lever carrying a cam 15 which contacts with the roller 16 secured to the lever 17. Up and down movement of the float 12 will cause the cam 15- to move the lever 17 upon the pivot 18 to thereby raise or lower the plunger 19 which contacts with a nut 20 which engages the lower end of the stud 21. The nut 20 and stud 21 clamp therebetween the top portion of the flexible bellows 22 which is adapted to expand or contract in accordance with steam or vacuum conditions in the boiler and which prevents escape of steam or water from the casing extension 10a.

A shell 23 surrounds the bellows 22 and serves also to guide the stud 21 in its reciprocating movement when actuated by the bellows 22. The stud 21, as shown in Fig. 1, is formed for removable engagement with the plunger 24 of the switch mechanism hereinafter described. The features of the apparatus set out above are described more in detail and claimed in the joint application of myself, Leo B. Miller and Everett N. Mc- Donald, filed May 8, 1926, Serial No. 107,649, and constitute no part of the switch mechanism forming the basis of the present application.

Secured to the section 10a of the casing is a third section 101) within which the switch mechanism is housed. The casing 106 is closed to the fluid in casing 10a by means of the bellows 22 and shell 24, described above.

The switch mechanism is supported on a back plate 25 which is secured to the three inwardly projecting lugs 26 by means of screws 27. A second plate 28 is secured to, but spaced from plate 25 by means of screws 29 and spacing tubes 30, respectively.

A bracket 31 is pivoted on pin 32 and ex tends between the plates 25 and 28, the said bracket being provided with an upwardly extending flange 33 provided with an opening 34. The flange is preferably provided with the designated graduations 35, as shown in Fig. 2. The bracket 31 is provided with an opening 36 through which extends the plungor 24, previously referred to, said plunger being pivoted to said bracket, at 37 whereby the reciprocating movement of the plunger causes the rocking of the bracket 31 on the pivot 32. The left end of the bracket 31 is shaped to provide the stops 38 and 39 which alternately engage with the spacing tube 30 to limit the movement or? the bracket. jacent the upper part of the plates 25 and 28 the switch arm 40 is pivoted as at 41, said arm carrying mercury contact tube 42 having contacts 43, 43, and a quantity of mercury therein. The tube 42 is carried by resilient bracket 44 which is secured to the end of arm 40 by screw 45. The vertical pivoted portion 40a of the arm 40 is shaped at its left end, as viewed in Fig. 4, to provide the stops 46 and 47 which alternately engage the interposed spacing tube 30, to limit the movement of the arm. The lower portion of the arm section 400; is provided with a cam sur face 48, hereinafter referred to. A link 49 connects the bracket 31 with the portion 400. of 40. The pivot 50 passes through an elongated opening 51 in the member 40o; whereby the latter can move through. a predetermined distance about its pivot independently of the link 49, thus providing, in effect, a lost motion connection.

A bar 52, having a threaded portion 53, is pivoted at 54 to the bracket 31, the said bar being slotted and the upper portion of the bracket 31 entering said slot. The bar 52 is cut away, as shown in Fig. 2, to provide clearonce for the link 49. A. roller 55 is secured in the slot of the bar 52 and bears against one or the other of the inclined faces oi the cam 48.

When the device is in the position shown in Figs. 2 and 4, the mercury tube 42 is tilted to cause the mercury to bridge the contacts 43 to close the circuit of the motor through the wires 56. The motor, not shown, will begin to pump fuel into the furnace and as the steam pressure rises the bellows 22 will expand and, if the pressure is sufiicient, will force the stud 21 and plunger 24 upwardly. Such movement of plunger 24 will be effected also should the water level of the boiler be lowered permitting the float 12 to recede and the plunger 19 to rise, as will be seen. The upward movement of the plunger 24, if suflicient, will cause the switch mechanism to move to off position and open the motor circuit until the steam pressure recedes or until the water supply is replenished, thus reventing damage to the heating equipment.

pward movement of the plunger 24, as viewed in Figs. 2 and 4, will cause bracket 31 to move about the pivot 32 in the counter clockwise direction, thereby moving link 49 upwardly. As the lost motion space provided in the connection between the link 43 and bracket member 40a is taken up, the lat- -mum and minimum pressures suitable for 21 ter member will be rotated counter clockwise also. Such movement of the member 400- will not take place, however, until the roller 55 has nearly reached the point of cam 48 due to the moving of the bar 52 to the left by the bracket 31 to which it is pivoted, at 54. As the roller 55 rides over the point of the cam, the force exerted by the roller on the opposite cam face, due to the weight 57 on threaded stem 53, and the motion transmitted by the link 49 will cause the bracket 40 to trip to the position shown in Fig. 5, in which the tube 42 is so tilted as to cause the mercury to flow away from the contacts 43, thus stopping the motor.

A weight 58 is adjustably secured to the front graduated flange 33 of the bracket 31 for setting the switch to open at predeter-- mined boiler conditions. The weight 58 is slotted, at 59, to receive the bracket 33, a knurled bolt 60 passing through the opening 61 and having a tapered portion 62 which engages the edges of the bracket 33 along the opening 34 when the bolt is screwed into the position shown in Fig. 3. By moving the .weight further to the right of the pivot 32 greater pressure will be required to lift the same and trip the switch mechanism, as will be clear. By moving the weight 57 farther to the right or left, the differential range over which the switch will operate can be regulated. F or instance, by setting the weight 58 at graduation L, the switch will open at a predetermined pressure in the boiler being reached. By setting the smaller or differential counter weight 57 in any given position, the switch mechanism will be moved to on position when the boiler pressure has dropped to the predetermined minimum, or when the supply of water has been replenished. It will be seen therefore that the adjustability of the weights 57 and 58 permits the selection of any one in a range of differentials between maxino particular installation. A set screw 57a is provided for securing the weight 57 against unintentional movement.

In heating plants employing the vacuum system the weight 58 is moved to the left of the center position of the bracket 31 whereby the weight tends to move the bracket to the position shown in Fig. 5, or off position. As long as the proper vacuum conditions are maintained the weight of member 58 is overcome and the mechanism held in the on or circuit closing position, but when the vacuum is lowered, permitting the bellows 22 to expand, the weight 58 trips the mechanism to off position.

Although I have shown a particular embodiment of my invention for the purpose of illustration, it will be seen that various changes may be made therein without departing from the of the appended claims. 13

I claim:

1. Apparatus of the class described comprising a pivoted member, a circuit controlling member carried by said-pivoted member, a second pivoted membenavlink connecting said pivoted members to each other, and

means for actuating said first pivoted memate with said link for rocking said". first piv.

oted member whereby said controlling memher is moved to circuit opening or closing positiou,

An electric switching mechenism of the class described comprising a mercury eiectric switch, a pivoted member supporting the same, a vertically movable member, means comprising a second pivoted member operatively associated with said movable memher and first pivoted member whereby said electric switch is given a quick si- ,pover action upon predetermined vertical movement of said vertically movabie member, and a pair of adiusting members connected to said second pivoted member ior controliing the opening and closing movement of said switch.

l, An electric circuit controlling device for use with mechanism comprising an expansibie member, said device comprising mercury contactor, a, pivoted bracket supporting the same, a second pivoted bracket, plunger actuateble by said expansibie member and being attached to said second bracket, and means comprising a verticaliy movable link connecting said brackets and a laterally movable bar operativeiy interposed between said brackets whereby said first bracket and Uni associated mercury contector Will be given e, quick snapover action upon predetermined movement of said expansible member.

5. An electric circuit controlling device for use with mechanism comprising an expansibie member, said device comprising e mercury contact member, a pivoted bracket support ing the same, a cam on said bracket, 2, second pivoted bracket operatively connected in seid expansible member to be moved thereby, s, link connecting said brackets, and a bar pivoted to said second bracket and opcretively engaging said cam, the arrangeine of seid link and bar being such that predetermined movement of said second bracket by said pansible member will efi'ect a quick snispover of said first bracket to move said contect member to circuit opening or closing position.

6. A circuit controlling device for use with mechanism comprising a pressure responsive member responsive to the pressures obtaining in a steam boiler, said device comprising a switch for controllinga motor circuit or the like, means for transmitting motion irom said responsive member to said switch for actuating the latter to and from circuit closing position, and reguiating means associated with, said transmitting means for permitting the actuation of said switch only under predetermined conditions of pressure, said regulating means comprising a pair of adjustable Weights, one adapted to be set whereby said switch will be moved to open position at pr determined maximum boiler pressure and the other ted to be set to permit the closing" of said switc predetermined minimum boiler pressure.

7. Apparatus of the class described com prising supportg" plete, bracket pivoted thereto, said bracset having cam, a mercury contact member c Tied by said bracket, a second bracket pivoted to said plate and having a fieige, adjustable Weight on said flange, bar pivoted to said second bracket and carrying a roller in engagement With said cam, a second adjustable Weight on said her, a linh pivoted to said second bracket and having a lost motion connection with said first bracket, an cxpensible membe' responsive to conditions pressure in a steam boiler or: the hire, and amember connecting said 821.}, onsisle member and said second bracket, mochasin. being so arranged that adjusting said Weights said contact member is moved to circuit opening or closing posi on by the expansion or contraction respect der n v of said expansible member onermined boiler conditions.

8. An (-siECnlllC circuit controlling device for use mechanism comprising a member responsive to pressure conditions of a steam boiler, said device comprising a liquid. contactor centre ing a motor circuit, e pivoted *er upon which said contec'tor is mounted, means for transmitting motion from pressure responsive member to said pivoted member for actuating the said contsctor to and irommotor-circuit closing position, reguiating means associated with transmitting means for permitting the actuation of the latter for opening and closing said contactor predetermined minimum and maximum boiler pressures, said reguiating means comprising a pair of memo bers adjustable for varying the dih erentials betweenthe maximum and minimum pres- 9. Apparatus of the class described comprising pair off pivoted members one of which is with a cam portion, e link coimecti'og said pivoted members to each other an electric switch on one of said pivoted members, and alaterally movable de vice pivoted to the other member havin a cam engaging portion to coact with said net, 5 cam portion, the arrangement being such that said laterally movable device and said cam portion move in opposite directions upon movement of said pivoted members whereby said cam engaging portion cooperates with 10 said cam portion for moving said switch with a snapaction from on to off position and vice versa.

10. An electric switch comprising tvvo pivotally mounted members one of which pro 15 vided a cam portion an electric switciiing mechanism mounted on one of said pivoted members, means for actuating the other of said pivoted members, it link connecting said pivoted members to each other through 2 a lost motion connection, and in member pivo'ted to said second pivoted end vided with a portion to said por. tion for effecting a quick snap-ovei said electric switching mechanism, as 11., An electric swi ch so otelly mounted members one videdmtii cem portion :a. ing mounted on pi having said cam portiom for acother of said mm membei" pivoted to ember and provides switch co 

